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Combined Optimal Dispatch of Thermal Power Generators and Energy Storage Considering Thermal Power Deep Peak Clipping and Wind Energy Emission Grading Punishment
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作者 Junhui Li Xuanzhong Luo +2 位作者 Changxing Ge Cuiping Li Changrong Wang 《Energy Engineering》 EI 2024年第4期869-893,共25页
Peak load and wind energy emission pressure rise more as wind energy penetration keeps growing,which affects the stabilization of the PS(power system).This paper suggests integrated optimal dispatching of thermal powe... Peak load and wind energy emission pressure rise more as wind energy penetration keeps growing,which affects the stabilization of the PS(power system).This paper suggests integrated optimal dispatching of thermal power generators and BESS(battery energy storage system)taking wind energy emission grading punishment and deep peak clipping into consideration.Firstly,in order to minimize wind abandonment,a hierarchical wind abandonment penalty strategy based on fuzzy control is designed and introduced,and the optimal grid-connected power of wind energy is determined as a result of minimizing the peak cutting cost of the system.Secondly,considering BESS and thermal power,the management approach of BESS-assisted virtual peak clipping of thermal power generators is aimed at reducing the degree of deep peak clipping of thermal power generators and optimizing the output of thermal power generators and the charging and discharging power of BESS.Finally,Give an example of how this strategy has been effective in reducing abandonment rates by 0.66% and 7.46% individually for different wind penetration programs,and the daily average can reduce the peak clipping power output of thermal power generators by 42.97 and 72.31 MWh and enhances the effect and economy of system peak clipping. 展开更多
关键词 BESS wind energy deep peak clipping virtual peak clipping wind energy emission grading punishment
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关于平面Clipping随机场的若干性质
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作者 徐全智 《电子科技大学学报》 EI CAS CSCD 北大核心 1990年第2期183-186,共4页
讨论了平面随机场关于水平 μ 的 clipping 随机场的各向同性,齐性,独立性和可分性的若干结果.
关键词 随机场 平面 clipping 工程数学
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脉冲噪声环境中基于clipping方法的鲁棒LPFT及其重排算法
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作者 李秀梅 鞠颖拓 《电路与系统学报》 CSCD 北大核心 2012年第2期13-17,共5页
为了更好地处理脉冲噪声环境中的时变信号,本文提出了基于clipping方法的鲁棒局部多项式傅里叶变换(LPFT)及其重排算法。首先利用clipping方法对信号中掺杂的脉冲噪声进行抑制,得到较好的信号时频分布表示,然后将重排算法与该鲁棒LPFT... 为了更好地处理脉冲噪声环境中的时变信号,本文提出了基于clipping方法的鲁棒局部多项式傅里叶变换(LPFT)及其重排算法。首先利用clipping方法对信号中掺杂的脉冲噪声进行抑制,得到较好的信号时频分布表示,然后将重排算法与该鲁棒LPFT相结合,以提高信号的时频聚集性。通过实验仿真可以看出,与基于中值滤波器的鲁棒LPFT相比,基于clipping方法的鲁棒LPFT同样能对被脉冲噪声干扰的信号给出较好的时频表示,而且其瞬时频率估计的最小均方误差(MSE)较低,计算量较小。并且,本文在基于clipping方法的鲁棒LPFT对掺杂脉冲噪声的信号进行处理的基础上,利用重排算法与其结合,有效增强了信号的时频聚集性。因此基于clipping方法的鲁棒LPFT及其重排算法是一种高效的处理脉冲噪声干扰信号及提高信号时频聚集性的方法。 展开更多
关键词 脉冲噪声 中值滤波器 clipping方法 局部多项式傅里叶变换(LPFT) 最小均方误差(MSE) 聚集 度(CM)
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用于降低OFDM系统峰均功率比的PTS-Clipping联合算法 被引量:8
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作者 洪善艳 张朝阳 《电路与系统学报》 CSCD 北大核心 2009年第4期105-110,共6页
基于IEEE 802.16d协议的OFDM传输系统,研究了峰均功率比(PAPR)较高的原因,在现有PARR降低算法的基础上,深入研究了算法之间的最佳联合准则,比较了两种可行的联合算法PTS-Clipping和Clipping-PTS之间的性能差异,得出了算法联合时的最佳... 基于IEEE 802.16d协议的OFDM传输系统,研究了峰均功率比(PAPR)较高的原因,在现有PARR降低算法的基础上,深入研究了算法之间的最佳联合准则,比较了两种可行的联合算法PTS-Clipping和Clipping-PTS之间的性能差异,得出了算法联合时的最佳级联顺序。Matlab仿真结果表明,PTS-Clipping是较优的联合算法,能够最大限度地利用现有算法的优势,在很好地降低PAPR的同时,又不会引入很大的计算量和限幅噪声。另外,本文得出的最佳联合准则具有通用性,适用于其他PAPR降低算法之间的联合。 展开更多
关键词 OFDM PAPR PTS clipping 联合算法
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基于CLIP和交叉注意力的多模态情感分析模型
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作者 陈燕 赖宇斌 +2 位作者 肖澳 廖宇翔 陈宁江 《郑州大学学报(工学版)》 CAS 北大核心 2024年第2期42-50,共9页
针对多模态情感分析中存在的标注数据量少、模态间融合不充分以及信息冗余等问题,提出了一种基于对比语言-图片训练(CLIP)和交叉注意力(CA)的多模态情感分析(MSA)模型CLIP-CA-MSA。首先,该模型使用CLIP预训练的BERT模型、PIFT模型来提... 针对多模态情感分析中存在的标注数据量少、模态间融合不充分以及信息冗余等问题,提出了一种基于对比语言-图片训练(CLIP)和交叉注意力(CA)的多模态情感分析(MSA)模型CLIP-CA-MSA。首先,该模型使用CLIP预训练的BERT模型、PIFT模型来提取视频特征向量与文本特征;其次,使用交叉注意力机制将图像特征向量和文本特征向量进行交互,以加强不同模态之间的信息传递;最后,利用不确定性损失特征融合后计算输出最终的情感分类结果。实验结果表明:该模型比其他多模态模型准确率提高5百分点至14百分点,F1值提高3百分点至12百分点,验证了该模型的优越性,并使用消融实验验证该模型各模块的有效性。该模型能够有效地利用多模态数据的互补性和相关性,同时利用不确定性损失来提高模型的鲁棒性和泛化能力。 展开更多
关键词 情感分析 多模态学习 交叉注意力 clip模型 TRANSFORMER 特征融合
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Analysis of wave clipping effects of plain reservoir artificial islands based on MIKE21 SW model 被引量:5
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作者 Yan Xiang Zhi-min Fu +2 位作者 Ying Meng Kai Zhang Zheng-fei Cheng 《Water Science and Engineering》 EI CAS CSCD 2019年第3期179-187,共9页
Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsati... Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsatisfactory plain reservoir wave-clipping schemes, a numerical method is proposed to predict and analyze waves in the reservoir in the presence of artificial islands, constructed from dredged sediment.The MIKE21 SW model is applied to a specific plain reservoir for finding the optimal artificial island parameters.The simulated wave height attenuation results are seen to agree well with empirically predicted values.Thus, the validity and reliability of the numerical model are established.Artificial islands at suitable locations in the reservoir can attenuate the wave heights by approximately 10%e30%, which justifies the efficacy of the clipping scheme making use of dredging and island construction. 展开更多
关键词 PLAIN RESERVOIRS Sediment deposition clipping via ISLAND construction MIKE21 SW Numerical simulation
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Role of endoscopic clipping in the treatment of oesophagealperforations 被引量:2
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作者 György Lázár Attila Paszt Eszter Mán 《World Journal of Gastrointestinal Endoscopy》 CAS 2016年第1期13-22,共10页
With advances in endoscopic technologies,endoscopic clips have been used widely and successfully in the treatment of various types of oesophageal perforations,anastomosis leakages and fistulas. Our aim was to summariz... With advances in endoscopic technologies,endoscopic clips have been used widely and successfully in the treatment of various types of oesophageal perforations,anastomosis leakages and fistulas. Our aim was to summarize the experience with two types of clips: The through-the-scope(TTS) clip and the over-the-scope clip(OTSC). We summarized the results of oesophageal perforation closure with endoscopic clips. We processed the data from 38 articles and 127 patients using PubM ed search. Based on evidence thus far,it can be stated that both clips can be used in the treatment of early(< 24 h),iatrogenic,spontaneous oesophageal perforations in the case of limited injury or contamination. TTS clips are efficacious in the treatment of 10 mm lesions,while bigger(< 20 mm) lesions can be treated successfully with OTSC clips,whose effectiveness is similar to that of surgical treatment. However,the clinical success rate is significantly lower in the case of fistulas and in the treatment of anastomosis insufficiency. Tough prospective randomized multicentre trials,which produce the largest amount of evidence,are still missing. Based on experience so far,endoscopic clips represent a possible therapeutic alternative to surgery in the treatment of oesophageal perforations under well-defined conditions. 展开更多
关键词 OESOPHAGEAL PERFORATION ENDOSCOPIC clipping Upper GASTROINTESTINAL PERFORATION ENDOSCOPY Over-thescopeclip
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Applications of multislice CT angiography in the surgical clipping and endovascular coiling of intracranial aneurysms 被引量:2
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作者 Wenhua Chen Yilin Yang +4 位作者 Wei Xing Ya Peng Jianguo Qiu Zhongming He Qi Wang 《The Journal of Biomedical Research》 CAS 2010年第6期467-473,共7页
Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage (SAH).The aim of our study was to assess the clinical usefulness of multislice computed tomography angiog... Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage (SAH).The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography (CTA) in the surgical and endovascular treatment of intracranial aneurysms.A total of 195 cases with 206 intracranial aneurysms underwent CTA.Fifty (24%) aneurysms underwent surgical clipping while 156 (76%) aneurysms underwent endovascular coiling.In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas,surgical treatment was successfully performed based on 16-slice CTA alone,and the other 36 aneurysms were clipped on the main basis of the CTA.The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully.Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms. 展开更多
关键词 intracranial aneurysm computed tomography angiography clipping COILING
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Clipping Alters the Response of Biomass Production to Experimental Warming: A Case Study in an Alpine Meadow on the Tibetan Plateau, China 被引量:8
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作者 FU Gang SUN Wei +5 位作者 YU Cheng-Qun ZHANG Xian-Zhou SHEN Zhen-Xi LI Yun-Long YANG Peng-Wan ZHOU Nan 《Journal of Mountain Science》 SCIE CSCD 2015年第4期935-942,共8页
Predicting how human activity will influence the response of alpine grasslands to future warming has many uncertainties.In this study, a field experiment with controlled warming and clipping was conducted in an alpine... Predicting how human activity will influence the response of alpine grasslands to future warming has many uncertainties.In this study, a field experiment with controlled warming and clipping was conducted in an alpine meadow at three elevations(4313 m, 4513 m and 4693 m) in Northern Tibet to test the hypothesis that clipping would alter warming effect on biomass production.Open top chambers(OTCs) were used to increase temperature since July,2008 and the OTCs increased air temperature by approximately 0.9o C ~ 1.8o C during the growing in2012.Clipping was conducted three times one year during growing season and the aboveground parts of all live plants were clipped to approximately 0.01 m in height using scissors since 2009.Gross primary production(GPP) was calculated from the Moderate-Resolution Imaging Spectroradiometer GPP algorithm and aboveground plant production was estimated using the surface-measured normalized difference vegetation index in 2012.Warming decreased the GPP, aboveground biomass(AGB) and aboveground net primary production(ANPP) at all three elevations when clipping was not applied.In contrast, warming increased AGB at all three elevations, GPP at the two lower elevations and ANPP at the two higher elevations when clipping was applied.These findings show that clipping reduced the negative effect of warming on GPP, AGB and ANPP, suggesting that clipping may reduce the effect of climate warming on GPP, AGB and ANPP in alpine meadows on the Tibetan Plateau, and therefore, may be a viable strategy for mitigating the effects of climate change on grazing and animal husbandry on the Tibetan Plateau. 展开更多
关键词 clipping Gross primary production Open top chamber WARMING Alpine Meadow Tibetan Plateau
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A new hemostatic clip for endoscopic surgery that can maintain blood flow after clipping 被引量:1
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作者 Kyoung Won Nam Sang Bong Lee +2 位作者 In Young Kim Kwang Gi Kim Sang Jae Park 《World Journal of Gastroenterology》 SCIE CAS 2014年第5期1325-1331,共7页
AIM: To develop a new hemostatic device for endoscopic surgery that can control the bleeding without completely occluding the bleeding vessel.
关键词 Vessel bleeding HEMOSTASIS Hemostatic clip Laparoscopic surgery Endoscopic surgery
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Reduction of the Clipping Noise for OFDM/OQAM System 被引量:2
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作者 Guobing Cheng Qifu Lv +3 位作者 Shaoqian Li Lisha Gong Binhong Dong Su Hu 《Communications and Network》 2013年第3期394-397,共4页
Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/O... Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/OQAM has also the intrinsic disadvantage of high peak-to-average-power ratio (PAPR) that should be alleviated. This paper focuses on the reduction of the clipping noise and out-of band radiation caused by the clipping process. The basic principle is to estimate the clipping noise and then eliminate it from the received signal. Analysis and simulation results show that, with one time iteration, the proposed method can effectively improve the bit error ratio (BER) performance. 展开更多
关键词 OFDM/OQAM PAPR REDUCTION clipping Noise
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Clipping prevents perforation in large, flat polyps 被引量:1
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作者 Daniel Luba Mona Raphael +3 位作者 Dayna Zimmerman Joseph Luba Jon Detka James DiSario 《World Journal of Gastrointestinal Endoscopy》 CAS 2017年第3期133-138,共6页
AIM To determine if prophylactic clipping of post-polypectomy endoscopic mucosal resection(EMR) mucosal defects of large,flat,right sided polyps prevents perforations.METHODS IRB approved review of all colonoscopies,a... AIM To determine if prophylactic clipping of post-polypectomy endoscopic mucosal resection(EMR) mucosal defects of large,flat,right sided polyps prevents perforations.METHODS IRB approved review of all colonoscopies,and prospective data collection of grasp and snare EMR performed by 2 endoscopists between January 1,2010 and March 31,2014 in a community ambulatory endoscopy center.The study consisted of two phases.In the first phase,all right-sided,flat polyps greater than or equal to 1.2 cm in size were removed using the grasp and snare technique.Clipping was done at the discretion of the endoscopist.In the second phase,all mucosal defects were closed using resolution clips.Phase 2 of the study was powered to detect a statistically significant difference in perforation rate with 148 EMRs,if less than or equal to 2 perforations occurred.RESULTS In phase 1 of the study,2121 colonoscopies were performed.Seventy-five patients had 95 large polyps removed.There were 4 perforations in 95 polypectomies(4.2%).The perforations occurred in polyps ranging in size from 1.5 cm to 2.5 cm.In phase 2,there were 2464 colonoscopies performed.One hundred and sixteen patients had 151 large polyps removed,and all mucosal defects were clipped.There were no perforations(P=0.0016).There were no post-polypectomy hemorrhages in either phase.An average of 2.15 clips were required to close the mucosal defects.The median time to perform the polypectomy and clipping was 13 min,and the median procedure duration was 40 min.Five percent of all patients undergoing colonoscopy in our community based,ambulatory endoscopy center had flat,right sided polyps greater than or equal to 1.2 cm in size.CONCLUSION Prophylactic clipping of the mucosal resection defect of large,right-sided,flat polyps reduces the incidence of perforation. 展开更多
关键词 Flat polyps COMPLICATIONS PERFORATION POLYPECTOMY Prevalence clipping Endoscopic mucosal resection
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Human Nail Clippings as a Source of DNA for Genetic Studies 被引量:2
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作者 Le Truong Hannah Lui Park +5 位作者 Seong Sil Chang Argyrios Ziogas Susan L. Neuhausen Sophia S. Wang Leslie Bernstein Hoda Anton-Culver 《Open Journal of Epidemiology》 2015年第1期41-50,共10页
Blood samples have traditionally been used as the main source of DNA for genetic analysis. How-ever, this source can be difficult in terms of collection, transportation, and long-term storage. In this study, we invest... Blood samples have traditionally been used as the main source of DNA for genetic analysis. How-ever, this source can be difficult in terms of collection, transportation, and long-term storage. In this study, we investigated whether human nail clippings could be used as a source of DNA for SNP genotyping, null-allele detection, and whole-genome amplification. From extracted nail DNA, we achieved amplicons up to a length of ~400 bp and >96% concordance for SNP genotyping and 100% concordance for null-allele detection compared to DNA derived from matched blood sam-ples. For whole-genome amplification, OmniPlex performed better than Multiple Displacement Amplification with a success rate of 89.3% and 76.8% for SNP genotyping and null-allele detection, respectively. Concordance was ~98% for both methods. When combined with OmniPlex whole-genome amplification, human nail clippings could potentially be used as an alternative to whole blood as a less invasive and more convenient source of DNA for genotyping studies. 展开更多
关键词 Single NUCLEOTIDE Polymorphism (SNP) NAIL clippings GENOTYPING WHOLE GENOME Amplification (WGA)
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基于CLIP与注意力机制的跨模态哈希检索算法 被引量:1
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作者 党张敏 喻崇仁 +3 位作者 殷双飞 张宏娟 陕振 马连志 《计算机工程与设计》 北大核心 2024年第3期852-858,共7页
针对传统无监督跨模态检索算法提取样本内部与样本之间的关联语义不充分,导致检索准确率低的问题,提出一种基于CLIP与注意力融合机制的无监督跨模态哈希检索算法CAFM_Net。将多模态预训练模型CLIP运用到样本特征提取阶段,从不同维度挖... 针对传统无监督跨模态检索算法提取样本内部与样本之间的关联语义不充分,导致检索准确率低的问题,提出一种基于CLIP与注意力融合机制的无监督跨模态哈希检索算法CAFM_Net。将多模态预训练模型CLIP运用到样本特征提取阶段,从不同维度挖掘数据的相似信息;使用注意力融合机制对提取的特征进行处理,加强显著区域的权重;引入对抗学习的思想设计模态分类器,生成更趋于语义一致性的跨模态数据哈希编码。与现有的代表性哈希方法相比,CAFM_Net在多模态检索任务上准确率提升至少11%与9%。 展开更多
关键词 无监督哈希 跨模态检索 clip 注意力融合 对抗学习 深度学习 TRANSFORMER
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The Line Clipping Algorithm Basing on Affine Transformation 被引量:1
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作者 Wenjun Huang 《Intelligent Information Management》 2010年第6期380-385,共6页
A new algorithm for clipping line segments by a rectangular window on rectangular coordinate system is presented in this paper. The algorithm is very different to the other line clipping algorithms. For the line segme... A new algorithm for clipping line segments by a rectangular window on rectangular coordinate system is presented in this paper. The algorithm is very different to the other line clipping algorithms. For the line segments that cannot be identified as completely inside or outside the window by simple testings, this algorithm applies affine transformations (the shearing transformations) to the line segments and the window, and changes the slopes of the line segments and the shape of the window. Thus, it is clear for the line segment to be outside or inside of the window. If the line segments intersect the window, the algorithm immediately (no solving equations) gets the intersection points. Having applied the inverse transformations to the intersection points, the algorithm has the final results. The algorithm is successful to avoid the complex classifications and computations. Besides, the algorithm is effective to simplify the processes of finding the intersection points. Comparing to some classical algorithms, the algorithm of this paper is faster for clipping line segments and more efficient for calculations. 展开更多
关键词 COMPUTER GRAPHICS Line clipping ALGORITHM AFFINE TRANSFORMATION
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Outcomes of early physiotherapy in patients with cerebral aneurysms treated by surgical clipping or endovascular embolization 被引量:1
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作者 Arzu Guclu-Gunduz Sevil Bilgin +1 位作者 Nezire Kse Hakan Oruckaptan 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第24期1900-1905,共6页
Early physiotherapy was given to 124 patients with ruptured or unruptured cerebral aneurysms who were treated by surgical clipping or endovascular embolization.Patients were divided into four groups according to their... Early physiotherapy was given to 124 patients with ruptured or unruptured cerebral aneurysms who were treated by surgical clipping or endovascular embolization.Patients were divided into four groups according to their Hunt and Hess grade at admission and aneurysm treatment modality: Group 1,Hunt and Hess grade≤II and surgical clipping;Group 2,Hunt and Hess grade≤II and endovascular embolization;Group 3,Hunt and Hess grade≥III and surgical clipping;Group 4,Hunt and Hess grade≥III and endovascular embolization.Level of consciousness was evaluated using the Glasgow Coma Scale,functional status using the Glasgow Outcome Scale,level of the mobility using the Mobility Scale for acute stroke patients,and independence in activities of daily living using the Barthel Index.After early physiotherapy,the level of consciousness and functional status improved significantly in Groups 1,3,and 4;mobility improved significantly in all groups;and independence in activities of daily living improved significantly in Groups 1 and 3.At discharge, Groups 1 and 2 had better functional status than Groups 3 and 4.Level of consciousness,functional status,mobility and independence in activities of daily living improved after early physiotherapy. These findings suggest that early physiotherapy improved the prognosis of patients with cerebral aneurysms who were treated by surgical clipping or endovascular embolization.Patients with a worse clinical status at presentation had a poorer functional status at discharge.The outcome of physiotherapy was not affected by whether surgical clipping or endovascular embolization was chosen for treatment of the aneurysm. 展开更多
关键词 cerebral aneurysm Hunt and Hess grade Glasgow Coma Scale Glasgow Outcome Scale functional status surgical clipping endovascular treatment PHYSIOTHERAPY neural regeneration
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A Strategy of Signal Detection for Performance Improvement in Clipping Based OFDM System 被引量:1
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作者 Jae-Hyun Ro Won-Seok Lee +2 位作者 Min-Goo Kang Dae-Ki Hong Hyoung-Kyu Song 《Computers, Materials & Continua》 SCIE EI 2020年第7期181-191,共11页
In this paper,the supervised Deep Neural Network(DNN)based signal detection is analyzed for combating with nonlinear distortions efficiently and improving error performances in clipping based Orthogonal Frequency Divi... In this paper,the supervised Deep Neural Network(DNN)based signal detection is analyzed for combating with nonlinear distortions efficiently and improving error performances in clipping based Orthogonal Frequency Division Multiplexing(OFDM)ssystem.One of the main disadvantages for the OFDM is the high Peak to Average Power Ratio(PAPR).The clipping is a simple method for the PAPR reduction.However,an effect of the clipping is nonlinear distortion,and estimations for transmitting symbols are difficult despite a Maximum Likelihood(ML)detection at the receiver.The DNN based online signal detection uses the offline learning model where all weights and biases at fully-connected layers are set to overcome nonlinear distortions by using training data sets.Thus,this paper introduces the required processes for the online signal detection and offline learning,and compares error performances with the ML detection in the clipping-based OFDM systems.In simulation results,the DNN based signal detection has better error performance than the conventional ML detection in multi-path fading wireless channel.The performance improvement is large as the complexity of system is increased such as huge Multiple Input Multiple Output(MIMO)system and high clipping rate. 展开更多
关键词 clipping DNN ML nonlinear distortion OFDM
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联合LDPC码与clipping降OFDM系统峰均比的方法 被引量:1
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作者 李春鹏 王春华 《计算机应用研究》 CSCD 北大核心 2010年第11期4257-4259,共3页
针对正交频分复用(OFDM)系统中存在的高峰均比问题,提出了一种简单而有效的降低峰均比(PA-PR)的联合方法,即将低密度奇偶校验码(LDPC)与传统的限幅(clipping)技术相结合的方法。该方法通过clip-ping技术降低OFDM信号的PAPR,同时结合LDP... 针对正交频分复用(OFDM)系统中存在的高峰均比问题,提出了一种简单而有效的降低峰均比(PA-PR)的联合方法,即将低密度奇偶校验码(LDPC)与传统的限幅(clipping)技术相结合的方法。该方法通过clip-ping技术降低OFDM信号的PAPR,同时结合LDPC码改善clipping技术带来的系统误比特率(BER)恶化与频域滤波降低带外功率辐射。MATLAB仿真结果表明,该方案能够简单而有效地降低PAPR并提高系统的BER性能,以及抑制带外功率辐射,证明了该联合方法的有效性。 展开更多
关键词 正交频分复用 峰均功率比 低密度奇偶校验码 限幅
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Over-the-scope-clipping system for anastomotic leak after colorectal surgery:Report of two cases 被引量:3
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作者 Hirotoshi Kobayashi Akifumi Kikuchi +5 位作者 Satoshi Okazaki Megumi Ishiguro Toshiaki Ishikawa Satoru Iida Hiroyuki Uetake Kenichi Sugihara 《World Journal of Gastroenterology》 SCIE CAS 2014年第24期7984-7987,共4页
An anastomotic leak is one of the major complications following colorectal surgery.Standard treatments for anastomotic leak are total parenteral nutrition or temporary ileostomy.The over-the-scope-clipping(OTSC)system... An anastomotic leak is one of the major complications following colorectal surgery.Standard treatments for anastomotic leak are total parenteral nutrition or temporary ileostomy.The over-the-scope-clipping(OTSC)system was originally developed to treat intestinal perforation or to close the tissue after natural orifice transluminal endoscopic surgery.Two cases of successful management of an anastomotic leak after colorectal surgery using the OTSC system are reported.One patient avoided a temporary ileostomy.In the other,hospitalization was shortened by the use of the OTSC system.The OTSC system can be a potential option in the management of anastomotic leaks after colorectal surgery. 展开更多
关键词 Over-the-scope-clipping Colorectal cancer Anastomotic leak Colorectal surgery Double stapling technique
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Signal Clipping at Transmitter and Receiver of O-OFDM for VLC under Optical Power Constraint 被引量:2
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作者 Liang Xia Xiaoqian Wang +6 位作者 Zhiwen Sun Zhitian Cheng Jing Jin Yifei Yuan Guangyi Liu Tao Jiang Yuhong Huang 《China Communications》 SCIE CSCD 2022年第6期154-168,共15页
Visible light communications(VLC)is considered as an effective supplement technology for next-generation(6G)communications due to its abundant spectrum,high power efficiency and easy deployment.Optical orthogonal freq... Visible light communications(VLC)is considered as an effective supplement technology for next-generation(6G)communications due to its abundant spectrum,high power efficiency and easy deployment.Optical orthogonal frequency division multiplexing(O-OFDM)is a common technology to obtain further promotion.In this paper,two typical O-OFDM schemes direct current biased O-OFDM(DCO-OFDM)and asymmetrically clipped O-OFDM(ACO-OFDM)are analyzed in terms of signal clipping at both transmitter and receiver under the constraints of maximum optical power and non-negative optical power.And effective electrical SNR models after signal clipping are proposed and verified by link simulation.Then a noise cancellation scheme is proposed based on received signal clipping and is proved to bring a significant gain for ACO-OFDM.By system simulation,we find that under a certain optical power limitation,most users can achieve above 4 Gbps in indoor scenario when modulation bandwidth of the light emit diode(LED)or laser diode(LD)is 1 GHz.Therefore,it can be expected that the throughput could reach tens Gbps when the LED/LD modulation bandwidth is increased and multiple LEDs/LDs are deployed. 展开更多
关键词 6G visible light communications optical orthogonal frequency division multiplexing clipping bit error rate THROUGHPUT
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